Blockchain Support
Supported EVM chains and how to access them through 256 Blocks
256 Blocks provides access to multiple EVM-compatible blockchains through a unified API. All chains support both mainnet and testnet environments.
Supported Chains
| Chain | Mainnet | Testnet |
|---|---|---|
| Ethereum | /ethereum | /ethereum-testnet (sepolia) |
| Base | /base | /base-testnet (sepolia) |
| Arbitrum One | /arbitrum | /arbitrum-testnet (sepolia) |
| Optimism | /optimism | /optimism-testnet (sepolia) |
| Polygon PoS | /polygon | /polygon-testnet (amoy) |
| BNB Smart Chain | /bsc | /bsc-testnet |
RPC URLs
Full RPC URLs are generated for each endpoint you create. To view your RPC URLs:
- Go to the Endpoints page
- Select an endpoint
- The RPC URLs section shows the full URL for each chain
URLs follow the format:
https://rpc.256blocks.com/{endpoint-key}/{chain-path}For example, to access Ethereum mainnet:
https://rpc.256blocks.com/abc123/ethereumIntegrating with SDKs
256 Blocks RPC endpoints work with any Ethereum-compatible SDK. See Integrations for detailed guides on:
- ethers.js
- viem
- web3.js
- wagmi
- MCP clients